CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Retained Earnings
BALANCE at Dec. 31, 2009	$ 212,275	$ 1,215	$ 152,051	$ 59,009
BALANCE (in shares) at Dec. 31, 2009		12,146
Increase (Decrease) in Stockholders' Equity
Net income	36,938	0	0	36,938
Issuance of stock through compensation plans, including income tax benefits, shares		9
Issuance of stock through compensation plans, including income tax benefits, Value	239	0	239	0
BALANCE at Dec. 31, 2010	249,452	1,215	152,290	95,947
BALANCE (in shares) at Dec. 31, 2010		12,155
Increase (Decrease) in Stockholders' Equity
Net income	93,823	0	0	93,823
Issuance of stock through compensation plans, including income tax benefits, shares		9
Issuance of stock through compensation plans, including income tax benefits, Value	226	1	225	0
BALANCE at Dec. 31, 2011	343,501	1,216	152,515	189,770
BALANCE (in shares) at Dec. 31, 2011		12,164
Increase (Decrease) in Stockholders' Equity
Net income	35,103	0	0	35,103
Issuance of stock through compensation plans, including income tax benefits, shares		1
Issuance of stock through compensation plans, including income tax benefits, Value	12	0	12	0
BALANCE at Dec. 31, 2012	$ 378,616	$ 1,216	$ 152,527	$ 224,873
BALANCE (in shares) at Dec. 31, 2012		12,165